Activationless charge transport across 4.5 to 22 nm in molecular electronic junctions

In this work, we bridge the gap between short-range tunneling in molecular junctions and activated hopping in bulk organic films, and greatly extend the distance range of charge transport in molecular electronic devices. Three distinct transport mechanisms were observed for 4.5–22-nm-thick oligo(thiophene) layers between carbon contacts, with tunneling operative when d < 8 nm, activated hopping when d > 16 nm for high temperatures and low bias, and a third mechanism consistent with field-induced ionization of highest occupied molecular orbitals or interface states to generate charge carriers when d = 8–22 nm. Transport in the 8–22-nm range is weakly temperature dependent, with a field-dependent activation barrier that becomes negligible at moderate bias. We thus report here a unique, activationless transport mechanism, operative over 8–22-nm distances without involving hopping, which severely limits carrier mobility and device lifetime in organic semiconductors. Charge transport in molecular electronic junctions can thus be effective for transport distances significantly greater than the 1–5 nm associated with quantum-mechanical tunneling.     

Déficit de alfa-1-antitripsina asociado a la variante Matawa

The most common deficiency alleles for alpha-1-antitrypsin deficiency (AATD) are Pi*S and Pi*S, but there are also other deficiency variants.     

Glycated albumin as a glycaemic marker in patients with advanced chronic kidney disease and anaemia: a preliminary report

Abstract

Background: The association between glycated albumin (GA) and glycaemic status has not been fully described in patients with advanced chronic kidney disease (CKD) in relation to anaemia. The aim of this study was to evaluate the relationship between GA and fasting plasma glucose (FPG) and HbA1c in patients with advanced CKD and to evaluate the influence of anaemia in such relationship.

Materials and methods: Patients with CKD stage 4 or 5 were included in the study. eGFR was calculated by the CKD-EPI creatinine equation. Plasma GA was measured by an enzymatic method.

Results: Eighty-one patients were included in the study, 46 (57%) were males; the mean age was 67?±?14?years. HbA1c was correlated with Hb (r?=?0.39; p?=?.0003), and no significant correlation was detected between plasma GA and serum albumin (p?=?.82). A significant association between FPG and GA (r²?=?0.41; p?r²?=?0.42; p?r²?=?0.55; p?Conclusions: GA, alone or in combination with other biomarkers, can be considered for the evaluation of glycaemic status in patients with advanced CKD and severe anaemia.     

Safety,Tolerability, Pharmacokinetics,and Antiviral Activity of GSK2336805, an Inhibitor of Hepatitis C Virus (HCV) NS5A,in Healthy Subjects and Subjects Chronically Infected with HCV Genotype 1

GSK2336805 is an orally bioavailable hepatitis C virus (HCV) inhibitor working through an NS5A-mediated mechanism. This first-time-in-human study was conducted to assess the safety, tolerability, pharmacokinetics, metabolism, and efficacy of GSK2336805 in healthy subjects and subjects infected with HCV genotype 1. We performed a three-part, randomized, double-blind, placebo-controlled study in 46 healthy subjects and 23 HCV-infected subjects. After an overnight fast, healthy subjects received GSK2336805 as 10 mg, 30 mg, 30 mg plus food, and 60 mg in a single dose and 10 mg (7 days), 30 mg (7 days), and 75 mg (14 days) in a once-daily multiple dose. Subjects with HCV received GSK2336805 as a 1- to 120-mg single dose. In subjects with HCV, reductions in HCV RNA were observed within 4 h and a single dose of GSK2336805 of ≥10 mg resulted in a statistically significant ≥2-log reduction in HCV RNA compared with placebo at 24 h postdose. GSK2336805 was readily absorbed in all subjects, and the half-life (t_1/2) was suitable for once-daily dosing. Administration of GSK2336805 with food had no effect on plasma GSK2336805 exposure; however, absorption was delayed, with a median t_max (time to maximum concentration of drug in serum) of 4.5 versus 2.0 h. Twenty subjects who received GSK2336805 experienced mild to moderate adverse events; none were serious. GSK2336805 was well tolerated and exhibited rapid, significant antiviral activity after a single dose in HCV-infected subjects. These results support the conduct of further studies evaluating GSK2336805 administered once daily for longer durations in combination with peginterferon, ribavirin, and other direct-acting antivirals. (This study has been registered at ClinicalTrials.gov under registration no. {"type":"clinical-trial","attrs":{"text":"NCT01277692","term_id":"NCT01277692"}}NCT01277692.)     

Mental health and psychosocial impact of the COVID-19 pandemic and social distancing measures among young adults in Bogotá, Colombia

We sought to explore mental health and psychosocial impact among young people (18 to 24 years old) in Bogotá during the first months of the COVID-19 pandemic.MethodsWe carried a cross sectional study using a web-based survey to assess mental health and personal impact among 18 to 24 years old living in Bogotá during the first 4 months of the 2020 COVID-19 pandemic lockdown. The depressive symptoms were measured with PHQ-8 and anxiety symptoms with (GAD-7). We also designed a questionnaire exploring changes in personal, family and social life.ResultsOverall, 23% of the sample (n = 834) reported mild depressive symptoms (males 24% and females 23%); 29% reported moderate depressive symptoms (males 28%, females 30%); 22% moderate-severe symptoms (males 20%, females 23%) and 17% severe symptoms (males 15%, females 17%). Mild anxiety symptoms were reported by 29% of the sample (males 30%, females 29%); moderate anxiety symptoms by 29% (males 26%, females 30%); moderate-severe 18% (males 15%, females 20%) and severe anxiety by 6.0% (males 6.0% and females 6.0%). High symptoms of depression (PHQ-8 ≥ 10) were associated with being female, considering that the quarantine was stressful, having one member of the family losing their job, worsening of family relationships, decrease of physical activity and having a less nutritious diet. Having high anxiety symptoms (GAD-7 ≥ 10) were associated with sometimes not having enough money to buy food.ConclusionsThe first months of the pandemic lockdown were associated with high depressive and anxiety symptoms among young persons living in Bogotá, Colombia. Increasing public health measures to provide support for young people is needed during lockdowns and it is necessary to further explore the long-term mental health impact due to personal, family and social changes brought by the COVID-19 pandemic.     

Clinical and biochemical approach to the neonate with a suspected inborn error of amino acid and organic acid metabolism

Disorders of amino acid and organic acid metabolism collectively represent a group of over 70 inherited diseases that are most frequently encountered in the neonatal period. A neonate with clinical symptoms caused by one of these disorders is a real clinical emergency, a situation complicated by the similarities to the manifestations seen in sepsis or asphyxia. Delay of diagnosis and proper treatment often results in severe morbidity and high mortality. The vast majority of these patients are likely to be transferred to a neonatal intensive care unit, suggesting that amino acid and organic acid biochemical screenings should be performed in these newborns routinely at admission. The analysis of amino acids and acylcarnitines in blood spots by tandem mass spectrometry has the potential to significantly improve the morbidity and mortality rates of metabolic disorders with neonatal presentation. In the case of disorders lacking an effective treatment, an early diagnosis could lead to proper genetic counseling of the parents and to the option of reliable prenatal diagnosis of future pregnancies. This review offers an updated summary of the clinical, biochemical, and therapeutic features of the aminoacidopathies and organic acidurias most likely to be encountered in neonatal clinical practice.     

Serogroup C Neisseria meningitidis invasive infection: analysis of the possible vaccination strategies for a mass campaign

The serogroup C meningococcal conjugate vaccine is available since 1999. In the absence of randomized controlled trials that support a specific schedule, each country has adopted different vaccination programmes. Hereby, we analyse positive and negative aspects of the different vaccination strategies. Conclusion: While waiting for the introduction of other antimeningococcal vaccines, covering also for the Group B meningococci, further studies on effectiveness of an optimal schedule to be adopted in European countries are needed.